Photographic element having polycarbonate sub-layer



March 13, 1962 A. OSSENBRUNNER ETAL 3,025,163

PHOTOGRAPHIC ELEMENT HAVING POLYCARBONATE SUB-LAYER Filed March 19, 1958 GE LAT/N0 SILVER -HALlDE-EMULS/0N SUBB/NG LAYER POLYCARBONATE INTERMEDIATE LAYER CELLULOSE ESTER SUPPORT BY w -25M W A TTORNEYS 3,025,163 r PHOTOGRAPHIC ELEMENT HAVING POLY- I CARBONATE SUB-LAYER Armin Ossenbrunner and Helfried kusen, and Peter Kruck, Koln-Stammheim, Germany, assignors to Agfa Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany Filed Mar. 19,1958, Ser. No. 722,464 Claims priority. application Germany Mar. 29, 1957 8 Claims. (Cl. 9687) The present invention relates to photographic film supports having improved anchoring layers for water permeable colloid layers, and more particularly to cellulose film supports having polycarbonate sublayers.

It is known that, with any photographic film material having a cellulose ester base, the danger of the material breaking is very high, especially with a low relative air humidity and of considerable thickness. With types of film which are subjected to strain in the camera or in the projector, this has a particularly disadvantageous effect.

United States Pateiit C Klockgether, Lever- I with gelatine silver halide emulsion layers This liability to breakage is caused by the .known great 1 brittleness of the gelatineused in the silver halide emul sion and by the unfavorable propertiesof the intermediate layer which is usualwith acetyl cellulose film and which promotes the bonding of the emulsion layer. This intermediate layer generally consists of gelatine, but; owing the acetyl cellulose, this gelatine in order. to produce,

m This anchoringin the su r to its low aflinity with must be incorporated in the surface an adequate bonding action. face is producedby the use of solvent in the base solution which have: a strong action on the film surface.

Furthermore, provision can be made for particularly good anchoring effect by the addition of acetyl cellulose,

which is soluble in acetone. After casting, the emulsion is united firmly to the gelatine under-layer, and, since,

this is incorporated in the surface of the film, the whole forms a rigid structure and consequently any breakage in the emulsion is transferred directly to the support.

Many experiments have been carried out for so modi- Patented Mar. 13, 1962 comesticky or tacky at the drying temperatures usual in :the manufacture ofacetyl cellulose film. Moreover, they can only be coated with ditficulty, so that another intermediate layer of nitrocellulose is still necessary.

It has nowbeen found that intermediate layers consisting wholly or in part of thermoplastic polycarbonates of high molecular weight, especially those derived from di-(monohydroxyaryl) alkanes,'are very suitable for improving the resistance to breakage without showing the disadvantages of the other processes.

Such polycarbonates correspond to the general formula:

wherein X is selected from thegroup consisting of monovalent cycloaliphatic and aromatic hydrocarbon fying the bonding layer that the maintenance of an adequate bonding effect is coupled with improved resist- These experiments have so far not If there is not.a verythorough-infilm surface, an inadequate bonding ance to breakage. led to any success. corporation into the residues, and n represents a number greater than 20,

especially than 50, R R and R standing for the same or for different radicals.

- Preferred polycarbonates are such in which R"s are hydrogen atoms and Rs are aliphatic or cycloaliphatic hydrocarbon residues of the kind mentioned above, whereby the two R's may be the same or different members of action is very quickly produced. When subiected to mechanical stress, the emulsion lifts from the film material and it floats off in the photographic baths.

'- tion are such of The difficulties canlargelybe avoided'by the ;use of}; I

intermediate layers the polarity of whichconforms better to the gelatine than the acetyl cellulose, so that they can be provided with a gelatine anchoring layer without the; gelatine being firmly incorporated into the, surface of. the intermediate layer. In this,,case, the resistance to,,.

breakage is clearly improved, sufiicient bonding being maintained, since the emulsion bonded to the intermediate layer can obviously still so that a fracture is not transmitted directly through this intermediate layer to the support; In other cases, the intermediate layer can be so applied that the fracture of the emulsion layer is taken up at the boundary surface between the intermediate layer and support. For example, the use of nitrocellulose lacquer intermediate layers has been proposed, it being known that these can be coated without additives with weakly acting solvents containing gelatine.

The use of nitrocellulose is however not desirable owing to the fact that it is readily inflammable.

The intermediate layers consisting of vinyl polymers as disclosed in USA. Patent No. 2,133,110 have the disadvantage that they are generally'thermoplastic and be be displaced on the film surface, 1

. the propyl, the isopropyl, the

the hexyl, the heptyl, the octyl, the nonyl, the decyl, the l-methyl-l-butenyl,

the group mentioned above, for instance an aliphatic or cycloaliphatic hydrocarbon residue.

Examples ofpolycarbonates according to the inventhe above formula, in which both R and all R"s are hydrogen atoms, further in which one R is a hydrogen atom,- the-other R-is the methyl, the ethyl, butyl, the isobutyl, the amyl,

the l-ethyl-l-pentenyl, the cyclopentyl, the cyclohexyl, thebenzyl, the 4 -m'eth yl-, ethyl-,

propyl-, i'sopropyl-gand butyl phenylen, the phenyl, and the furyl residue, and'all a different member of the ,hydrocarbon residues mentioned here above and all R"s group, the remaining R are hydrogen atoms, in which X is Z representing the carbon and atoms completing the cyclopentane or the cyclohexane ring and R is hydrogen, and such, in which each R represents a hydrogen atom or the same or a different member of the groups mentioned above and each R represents a member of the group consisting of the methyl, the ethyl, the propyl, the isopr'opyl, the n-butyl, the tert. butyl, the isobutyl, the tert. amyl, thecyc'lopentyl, the cyclohexyl, and the phenyl being hydrogen.

the group consisting" of by to 10'carbon atoms, ono:

having up to'4 carbon atoms as side- Rs are hydrogen atoms, in ;which each R is the same or Under these polycarbonates typical representatives are for instance the poly-(2,2-(4,4-dihydroxy-diphenylen)- propane-carbonate), the poly (2,2 (4,4-dihydroxy-diphenylen)-butane-carbonate), the poly-(2,2-(4,4'-dihydroxydiphenylen)-pentane-carbonate), the poly-(1,1-(4, 4'-dihydroxydiphenylen)-cyclohexane-carbonate), and the mixed poly (2,2 (4,4'-dihydroxy-diphenylen)-propaneand (4,4-dihydroxy-diphenylen)methane-carbonate).

For the formation of the polycarbonates, it is also possible to use mixtures of various di-monohydroxyaryl alkanes as well as mixtures of di-monohydroxyarylen alkanes with other dihydroxy compounds, such as aliphatic, cycloaliphatic dihydroxy compounds as well as aromatic dihydroxy compounds which are different from those mentioned above.

As examples of the accompanying dihydroxy compounds which may be used according to the invention, the following are named by way of example:

Aliphatic dihydroxy compounds such as: ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, thiodiglycol, ethylene dithiodiglyeol, the di-, and polyglycols produced from propyleneoxide-l,2, o, m, or p-xylylene glycol, propanediol-1,3, butanediol-1,3, butanediol-l,4, 2-methylpropanediol-L3, pentanediol-l,5, 2-ethylpropanediol-l,3, hexanediol-1,6, octanediol-1,8, l-ethylhexane diol-l,3, and decanediol-l,l0, cycloaliphatic dihydroxy compounds such as cyclohexanediol-l,4, cyclohexanediol-1,2, 2,2-(4,4'-dihydroxy-dicyclohexylen)-propane and 2,6-dihydroxydecahydronaphthalene and aromatic dihydroxy compounds such as hydroquinone, resorcinol,

pyrocatechol, 4,4-dihydroxydiphenyl, 2,2-dihydroxydiphenyl, 1,4-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,2-dihydroxynaphthalene, l,S-dihydroxynaphthalene, dihydroxyanthracene,

2,2-dihydroxydinaphthyl-l,I and o, m, p-hydroxybenzylalcohol.

These polycarbonates may be replaced wholly or partially by further polycarbonates. Such further thermoplastic polycarbonates of high molecular weight can be obtained by reacting dihydroxy diaryl sulphones or mixtures of dihydroxy diaryl sulphones with other bifunctional dihydroxy compounds and from dihydroxy diaryl ethers or dihydroxy diaryl thioeters or from mixtures of the said compounds with other dihydroxy compounds, according to German patent application No. F 17 168 IVc/39c (D.A.S. 1,007,996, published May 9, 1957), and from dihydroxy diaryl ethers or dihydroxy diaryl thioeters or from mixtures of the said compounds with other dihydroxy compounds according to German patent application Nos. F 21 459 IVb/39c and F 21 662 IVc/39c.

Further suitable polycarbonates are those which are derived from mixtures of aliphatic and/or cycloaliphatic dihydroxy compounds with at least one aromatic dihydroxy compound other than the above cited aromatic dihydroxy compounds.

In the dihydroxydiaryl sulphones used for forming the polycarbonates, the aryl residues can be the same or different. The aryl residues can furthermore carry hydrogen atoms or substituents which are incapable of taking part in the reaction to polycarbonates, e.g. the halogens and alkyl groups such as ethyl, methyl, propyl or tertiary butyl.

As examples of dihydroxydiaryl sulphones of the specified type, the following may be mentioned:

4,4'-dihydroxydiphenylsulphone, 2,2-dihydroxydiphenylsulphone, 3,3'-dihydroxydiphenylsulphone, 4,4-dihydroxy-2,2-dimethyldiphenyl-sulphone, 4,4-dihydroxy-3, 3'-dimethyl-diphenyl-sulphone, 2,2 dihydroxy 4,4 dimethyl-diphenyl-sulphone and 2,2-dihydroxy-1,l'-dinaphthyl-sulphones.

As examples of the other dihydroxy compounds which may be used in admixture with the dihydroxydiaryl sulphones if desired, there may be mentioned the following: ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, the corresponding thioglycols, di- 01' poly-glycols obtained from propylene oxide-1,2, propanediol-l,2, propanediol-l,3, butanediol-1,3, butanediol-1,4, 2-methylpropanediol-1,3, pentanediol-l,5, 2-ethylpropanediol-l,3, hexanediol-l,6, octanediol-1,8, 2-ethylhexanediol-l,3 and decanediol-l,l0; cyclohexanediol-l,4, cyclohexanediol-l,2, o-. p-, or m-xylene glycol, 2,2-(4,4'-dihydroxy dicyclohexyl) propane, 2,6 dihydroxy-decahydronaphthalene, hydroquinone, resorcinol, pyrocatechol, 4,4- dihydroxydiphenyl, 2,2 dihydroxydiphenyl, 1,4 dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1.Z-dihydroxynaphthalene, 1,5-dihydroxyanthracene, 2,2'-dihydroxydinaphthalene-1,l', and 0-, m-, or p-hydroxybenzylaleohol. Di-monohydroxyarylalkanes as disclosed in copending application Serial No. 577,362, filed April 4, 1956, and in British specification No. 772,627, such as di-(p-hydroxyphenyl)-methane, 2,2- di-(p-hydroxyphenyl)-propane, 1,1-di-(p-hydroxyphenyl)- cyclohexane, l,1-di-(p-hydroxy-m-methylphenyl) cyclohexane, 2,2 di (o-hydroxy-p-tert.-butylphenyl) -propane and 3,4-di-(p-hydroxy-phenyl)-hexane and 1,1-di-(p-hydroxy-phenyl) 1 phenyl-ethane, furthermore methane derivatives which carry besides two hydroxylaryl groups, a further alkyl residue with at least two, and a second alkyl residue with one or more carbon atoms, e.g. 2,2-di- (p-hydroxyphenyl) -butane, 2,2 di (p-hydroxyphenyD- pentane, 3,3-di-(p-hydroxyphenyl)-pentane, 2,2-d1-(p-hydroxyphenyl)-2-methylbutane, 2,2-di-(p-hydroxy-phenyl)- hexane, 2,2-di-(p-hydroxyphenyl)-4-methylpentane, 2,2- di (p hydroxyphcnyl)-heptane, 4,4-(p-hydroxyphenyl)- heptane and 2,2-di-(p-hydroxyphenyl)tridecane.

The polyesters may be produced it, for example, bischloro-carbonates of dihydroxy diaryl sulphones or mixture thereof with the aforementioned dihydroxy com pounds, "are condensed with dihydroxy diaryl sulphones, or mixtures thereof with other dihydroxy compounds. These condensations are suitably brought about in the presence of inert solvents and acid-binding agents such as tertiary amines as described for analogous processes in British specification No. 772,627.

A further method of carrying out the process consists in passing phosgene either into an aqueous alkali solution or suspension of the dihydroxy diaryl sulphone, optionally in the presence of other dihydroxy compounds and inert solvents, or into a solution or suspension of these materials in an inert solvent optionally in the pres ence of acid-binding agents such as tertiary amines also as described for analogous processes in British specification No. 772,627. According to both methods of carrying out the process it is an advantage to accelerate the polycondensation by adding to the reaction mixture quaternary ammonium compounds in the form of their free bases or as salts.

Finally it is also possible to produce the polycarbonates by inter-esterifying dihydroxy diaryl sulphones, optionally mixed with the aforementioned dihydroxy compounds and suitably in the presence of acidic or basic catalysts, with dialkyl or diaryl carbonates. The basic catalysts preferably used are suitably neutralized in the course of, or at the end of, the polycondensation by adding base-binding substances are especially suitable since an excess thereof can be removed by evaporation or sublimation from the melt.

For the production of the polycarbonates derived from diphenyl ethers and -thioethers diphenyl ethers and/or -thioethers may be used in which the two aryl radicals are the same or different.

The aryl radicals may further carry substituents which are incapable of reacting during the conversion into the poly-carbonates such as halogen, or alkyl groups such as the methyl-, ethyl-, propylor the tert. butyl group.

Suitable dihydroxy-diaryl ethers or -thioethers are, for example:

4.4'-dihydroxy-diphenyl ether, 4,4-dihydroxy-2,2'-dimethyldiphenyl ether, 4,4 dihydroxy 3,3 dimethyldiphenyl ether or their homologues, as well as 4,4'-dihydroxydiphenyl sulphide, 4,4 dihydroxy 2,2 dimethyldiphenyl-sulphide, 4,4 dihydroxy-3,3'-dimethyldiphenylsulphide and their homologues. The latter are readily obtainable by condensation of sulphur dichloride with the corresponding phenols.

The further dihydroxy compound which may be used in combination with the said ethers and thioethers may be the same as those disclosed above in connection with the production of polycarbonates derived from diaryl sulfones. The polycarbonates produced from the above ethers and thioethers or mixtures of said compounds with further dihydroxy compounds may be produced by the same methods as the polycarbonates derived from diarylsulphones and mixtures of said sulphones with further dihydro compounds.

For the production of polycarbonates derived from mixtures of aliphatic and/or cycloaliphatic dihydroxy compounds with aromatic dihydroxy compounds other than the above dihydroxy diarylalkanes, dihydroxydiarylsulfones, and dihydroxydiarylethers and -thioethers there may be used the following aromatic dihydroxy compounds:

Hydroquinone, resorcinol, pyrocatechol, 4,4 -dihydroxydiphenyl, 2,2-dihydroxydiphenyl, 1,4-dihydroxynaphthalene, 1,G-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,Z-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,4-dihydroxyquinoline, 2,2-dihydroxydinaphthyl-1,1 and mor p-hydroxybenzyl alcohol. As aliphatic or cycloaliphatic dihydroxy compounds to be used according to the invention, there may be named: ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, thiodiglycol, ethylene dithiodiglycol, propane diol-1,2, propanediol-l,3, butanediol-1,3, butanediol-1,4, 2-methylpropanediol-1,3, pentanediol-1,5, 2-ethylpropanediol-1,3, hexanediol-1,6, octanediol-1,8, 2-ethylhexanediol-l,3, decanediol-1,l0, cyclohexanediol-1,4, cyclohexanediol-1,2- 0-, mor p-xylylene glycol, 2,2'-(4,4- dihydroxydichlorohexyl)-propane, 4,4-dihydroxydicyclohexyl methane and 2,6-dihydroxydecahydronaphthalene.

The transformation of the foregoing dihydroxy compounds into high molecular polycarbonates can be carried out by the methods disclosed above.

The aforementioned polycarbonates derived from the disclosed sulphones, ethers and thioethers may be represented by way of example by the following formula:

in which R stands for one of the following bivalent radicals: SOFQ G G G O the phenyl radicals of which may be substituted and n stands for a whole number preferably greater than 10. The mixed polycarbonates may contain the following units:

6 Formulae I and II, these dihydroxy compounds can all be considered as bisphenols.

The polycarbonates may also be produced by the processes indicated in the following patents: British Patent 772,627; French Patents 1,149,261; 1,152,155; 1,152,156; 1,152,157; 1,152,158; Belgian Patents 546,375; 555,894.

The application of the polycarbonate intermediate layer to the organic cellulose ester film takes place from specific solvent mixtures, since otherwise adequate bonding to the support is not-produced. Certain mixtures of solvents and nonsolvents for acetyl cellulose and other organic cellulose esters, and preferably chlorinated hydrocarbons since the polycarbonate dissolves well in the latter, have proved to be particularly suitable.

Mixtures of methylene chloride and trichloroethylene, chloroform and benzene, methylene chloride, acetone and trichloroethylene are examples. The nonsolvents are preferably in quantities of 60 to 40 parts by weight and the solvent in quantities of 40 to 60 parts by weight.

The polycarbonates can be used alone, but can be admixed with other plastics, provided the various components are compatible with one another. Examples of such plastics are: nitrocellulose (nitrogen content 11.7- 12.3%), ethyl cellulose (ethoxyl content 48.049.5%) and co-polymers of ethylene and vinyl acetate or vinylpropionate preferably such containing 30 to 50 percent by weight of vinylester. It is possible in many cases to produce additional effects therewith.

These intermediate layers are preferably provided with a further anchoring or bonding layer varying from about 0.05 to 2 microns in thickness. Such additional layers may be produced from a mixture of (1) Gelatine and copolymers containing hydroxyl groups, preferably a partially saponified copolymer of vinyl chloride and vinyl acetate, or

(2) A polyvinyl alcohol mixed acetal obtained from polyvinyl alcohol and aldehydes with and without watersolubilising groups and co-polymers containing hydroxyl groups.

These mixtures are preferably applied from a solvent mixture which gives hardly any swelling of the polycarbonate, so that no incorporation into the surface of the intermediate polycarbonate layer takes place. The use of methanol to which a small proportion of acetone has been added has proved particularly satisfactory.

The intermediate polycarbonate layer must have a certain minimum thickness, since otherwise the preparation penetrates in spite of the slight attacking action, and this results in poor bonding and also in lower resistance to breakage.

It has proved to be desirable to use polycarbonates having a molecular weight of about 40,000-80,000. Substances havinghigher molecular weights are difficult to dissolve and dry on an irregular form, whereas a lower molecular weight produces less satisfactory film-forming properties and too easy swellability.

The aforementioned additional layer of gelatine and a polymer containing hydroxyl groups preferably consists essentially of gelatine and a partially hydrolysed copolymer of 40 to 60 parts by weight of vinyl chloride and 60 to 40 parts by weight of an organic vinyl ester, such as vinylacetate, vinylpropionate, vinylbutyrate, vinyl benzoate, this copolymer advantageously containing from 45 to 70% by Weight of vinyl chloride, 530% by weight of vinyl hydroxide and 10 to 40% by weight of organic vinyl ester. The proportion of gelatine with respect to the copolymer can fluctuate within Wide limits; it is however advantageous to use a ratio of 2:3 parts by weight of gelatine to 3:2 parts of copolymer. The coating solution has added thereto an organic carboxylic acid, such as acetic acid, propionic acid, phthalic acid, salicylic acid, maleic acid in amounts of about 5 to 50 percent calculated on the weight of gelatine. Furthermore, hardening agents for the gelatine can be incorporated into this auxiliary layer, for example formaldehyde or gyloxal. The

spasms 7 aforementioned components are dissolved in conventional organic solvents as disclosed above and the solutions are applied to the support by one of the known dipping processes.

The aforementioned mixed acetals can be obtained bya conventional process, for example by heating the components for several hours in methanolic solution with sulphuric acid as catalyst. Examples of aldehydes with water-solubilizing groups are aromatic aldehydes which are substituted in the aromatic nucleus by carboxyl, sulphonic acid or hydroxy groups, for example benzaldehyde-Z-sulphonic acid, benzaldehyde-2,2-disulphonic acid and p-hy- -droxy benzaldehyde. Examples of aldehydes without water-solubilizing groups are araliphatic and aliphatic aldehydes, for example benzaldehyde, tolyl aldehyde, pchlorobenzaldehyde and hydrocinnamaldehyde. For the bonding action which is to be produced, it is of decisive importance that both the hydrophilic and the by drophobic components shall be used. The degree of acetalisation can fluctuate within wide limits, but the best re-- sults are produced with products in which 50-60% of all hydroxyl groups of the polyvinyl alcohol are acetalised. The most favorable ratio between aldehydes with watersolubilizing groups and those without water-solubilizing groups depends upon the nature of the aldehydes. It has, however, been found that, in general, a molecular excess of aldehydes without water-solubilizing groups is necessary for the production of a sufficient degree of solubility in organic solvents.

The acid groups may be neutralized with bases capable of yielding water-soluble salts such as alkali metals (sodium, potassium, lithium) ammonia, amines such as primary, secondary and tertiary methyl-, ethyl-, propylamines, cyclohexylamine, morpholine, piperidine. For producing the intermediate layer, the mixed acetals are preferably dissolved in a proportion of 0.75 to 1.25% in a mixture of methanol and one or more other organic solvents, for example acetone, tetrahydrofurane or dioxane. For improving the bonding action, it may be advisable to add a small proportion of a partially saponified copolymer of vinyl chloride and an organic vinyl ester, for example vinyl acetate, vinyl propionate or vinyl butyrate, for example a paritially saponified copolymer of vinyl chloride and vinyl acetate. These partially saponified copolymers are produced by known methods by saponification in methanol solution with sulphuric acid as catalyst, merely the organic ester groups being partially saponified. Suitable saponified copolymers contain approximately 45- 70% by weight of vinyl chloride, 30% by weight of vinyl hydroxide and -40% by weight of vinyl acetate or another organic vinyl ester such as vinyl propionate, vinyl butyrate or vinyl benzoate. Copolymers of vinyl chloride and e s-unsaturated carboxylic acids or partially saponified copolymers of vinyl chloride and esters of the aforementioned acids can alternatively be used. The coating is advantageously produced by one of the conventional dipping processes.

With application speeds by the dipping process of 1.5 to 2.5m./min., concentrations of 3-5% of polycarbonates with the mean viscosity mentioned above have proved advisable. The thickness of the intermediate polycarbonate layer may amount to l to 10, preferably 2 to 5 microns.

The process will be explained in the following examples:

Example 1 An acetyl cellulose film (61.0% acetic acid) is treated with the following base or substrate solution by the dipping process:

30 g. of a polycarbonate of 4,4'-dihydroxydiphenyldimethyl methane,

400 cc. of methylene chloride, and

600 cc. of trichloroethylene.

i The layer is thoroughly dried at a temperature of C. and thereafter coated with the following solution:

9 g. of gelatine 3 g. of phthalic acid 3 g. of a partially saponified co-polymer of vinyl chloride and vinyl acetate having the following composition:

63.2% of vinyl chloride, 25.3% of vinyl alcohol, 11.5% of vinyl acetate,

610 cc. of methanol, and

390 cc. of acetone.

The film is thereafter provided with a gelatino silver halide emulsion layer having a thickness of 8 to 18 microns. The resistance to breaking is good; the bonding effect is adequate. It is true that the emulsion breaks at low relative air humidities, but the breakage is not transferred to the support.

Example 2 A film support of acetyl cellulose (59% acetic acid) and the usual plasticisers has applied thereto by a dipping process an intermediate layer consisting of the following solution:

10 g. of 4,4'-dihydroxydiphenyl methyl ethyl methane polycarbonate,

10 g. of cellulose nitrate,

600 cc. of ethyl acetate, and

400 cc. of methylene chloride.

The layer is dried at 90-1 10 C. and subbed with the following solution:

7 g. of gelatine,

2.3 g. of phthalic acid, 1.5 cc. of water,

303 cc. of methanol, 627 cc. of acetone and 0.25 g. of glyoxal.

After being dried, the film support is cast with a gelatino silver halide emulsion. It has the same properties as in Example 1.

Example 3 A film support of acetyl cellulose (57% combined acetic acid) has applied thereto an intermediate layer consisting of the following solution:

25 g. of 4,4'-dihydroxydiphenyl-methyl-ethyl methane polycarbonate,

250 cc. of ethyl acetate,

cc. of acetone, and

600 cc. of trichloroethylene.

After drying of the layer, the following solution is used for subbing purposes:

The film support cast with photographic emulsion has the properties indicated in Example 1.

Example 4 An acetyl cellulose film support has applied thereto an intermediate layer from the following solution:

20 g. of a polycarbonate of 4,4'-dihydroxydiphenyl dirnethyl methane,

5 g. of a co-polymer of ethylene and vinyl acetate (1:1),

600 cc. of methylene chloride, and

400 cc. of trichloroethylene.

After drying of the y the following solution is The film support cast with a gelatino silver halide emulsion has the properties indicated in Example 1.

The aforementioned combinations may not only be used for treating cellulose acetate films but also film supports of other organic cellulose esters such as cellulose acetate-butyrate, cellulose acetate-propionate. The film supports usually have a thickness varying between about 60 to 200 microns, preferably 80 to 120 microns.

In the accompanying drawing the FIGURE is an enlarged cross-sectional view of one type of structure according to the present invention. In this figure, 1 represents a support of an organic cellulose ester, 2 represents an intermediate polycarbonate layer, 3 represents a subbing layer, such as one composed of a mixture of gelatine and a polymer containing hydroxyl groups or of a mixed acetal produced from polyvinylalcohol and aldehydes having acid groups and such being free of acid groups, 4 represents a water-permeable colloid layer, such as a gelatine silver halide emulsion layer.

We claim:

1. A photographic element comprising a support composed of an acetyl cellulose ester; an intermediate layer comprising a high molecular weight linear thermoplastic polycarbonate coated on said support, said polycarbonate consisting essentially of recurring units of the formula:

C fl

OAOMHF a subbing layer coated on said polycarbonate layer and comprising a film-forming agent selected from the group consisting of (l) a mixed acetal of polyvinyl alcohol with an aldehyde devoid of water-solubilizing groups as well as an aldehyde containing a group selected from the class consisting of carboxylic and sulfonic acid groups and their water-soluble salts, and (2) a combination of gelatine with a partially hydrolyzed copolymer of vinyl chloride with a vinyl ester of a carboxylic acid; said subbing layer being coated with a gelatine-silver halide emulsion layer.

2. A photographic element comprising a support composed of an acetyl cellulose ester; an intermediate layer comprising a high molecular weight linear thermoplastic polycarbonate coated on said support, said polycarbonate consisting essentially of recurring units of the formula:

(32KB a subbing layer coated on said polycarbonate layer and comprising a film-forming agent selected from the group consisting of (1) a mixed acetal of polyvinyl alcohol with an aldehyde devoid of water-solubilizing groups as well as an aldehyde containing a group selected from the class consisting of carboxylic and sulfonic acid groups and their water-soluble salts, and (2) a combination of gelatine with a partially hydrolyzed copolymer of vinyl chloride with a vinyl ester of a carboxylic acid; said subbing layer being coated with a gelatine-silver halide emulsion layer.

3. A hydrophobic film comprising a cellulose acetate support 60-200 microns thick, an adjacent break-resistant layer l-lO microns thick of a film-forming resinous theri16 5iasa polycarbonate ring units of the formula:

R R R wherein X is selected from the group consisting of S, O,

and

wherein R and R are selected from the groups consisting of H, branched and unbranched monovalent aliphatic hydrocarbons containing up to 10 carbon atoms, monovalent cycloaliphatic hydrocarbons, monovalent araliphatic hydrocarbons containing up to 4 carbon atoms as side chains, phenyl and furyl, Z represents the carbon and hydrogen atoms which complete a cycloaliphatic ring, and R is a member selected from the group consisting of hydrogen, monovalent branched and unbranched aliphatic hydrocarbon radicals of up to 5 carbon atoms, monovalent cycloaliphatic hydrocarbon, and monovalent aromatic hydrocarbon radicals; and a gelatine-silver halide emulsion bonded to said break-resistant layer through a subbing layer of a mixed acetal of polyvinyl alcohol with (I) an aromatic aldehyde containing a water-solubilizing group and (II) an aldehyde free of water-solubilizing groups, 50 to 60% of the hydroxy groups being acetalized and the (II) aldehyde being in molar excess with respect to the (I) aldehyde.

4. The film of claim 3 wherein said subbing layer is a mixture of 2 to 3 parts gelatme by weight with 3 to 2 parts by weight of a partially hydrolyzed copolymer of vinyl chloride and a vinyl ester of a carboxylic acid, the copolymer being 45 to by weight vinyl chloride, 5 to 30% by weight vinyl hydroxide, and 10 to 40% by weight said vinyl ester.

5. The film of claim 3 wherein the subbing layer also contains a minor proportion of a partially saponified copolymer of vinyl chloride and a vinyl ester of a carboxylic acid, said copolymer being 45 to 70% by weight vinyl chloride, 5 to 30% by weight vinyl hydroxide, and 10 to 40% by weight said vinyl ester.

6. The film of claim 3 wherein the polycarbonate consists of recurring units resulting from the use of a mixture of dihydroxy compounds in the preparation of the polycarbonate, one portion of said dihydroxy compounds having the formula:

R R R R R R having a molecular weight of about 40,000 -80,000 and consisting essentially 0t recurwherein R is a member selected from the group consisting of ethyl and methyl.

References Cited in the file of this patent UNITED STATES PATENTS Alles et a1. Dec. 28, 1954 Saner Dec. 28, 1954 Caldwell July 16, 1957 Klockgether et a1 Feb. 17, 1959 

3. A HYDROPHOBIC FILM COMPRISING A CELLULOSE ACETATE SUPPORT 60-200 MICRONS THICK, AN ADJACENT BREAK-RESISTANT LAYER 1-10 MICRONS THICK OF A FILM-FORMING RESINOUS THERMOPLASTIC POLYCARBONATE HAVING A MOLECULAR WEIGHT OF ABOUT 40,000-80,000 AND CONSISTING ESSENTIALLY OF RECURRING UNITS OF THE FORMULA: 